Hot Water heat - Glycol? Other closed-system option?

Discussion in 'HVAC Heating & Cooling' started by LeBlanc, Nov 11, 2007.

  1. LeBlanc

    LeBlanc New Member

    Messages:
    25
    We purchased a vacation home on Houghton Lake, Michigan that has a Hot Water baseboard heat system. Since we will not live there full-time and may only visit a couple of times during the winter, we're not too thrilled with having to leave the heat "ON" all winter.

    We've been told we should never drain the hot water heat system because it's too difficult for the average homeowner to recharge. I'm probably less than average and am not seeking extra work for myself.

    We'd also like to turn the well pump off when we leave (it's a 300 foot deep well), but since we have to leave the heat on, that's not an option.

    If we could choose to do what we'd like, we would empty the hot water heater and heat system, drain supply lines, anti-freeze all drains and toilets, etc, and turn all of the power off.

    A friend said he thought hot water heat systems could be charged with glycol and that it would then be a freeze proof "closed system." Can anyone point me in the right direction if we can convert the system to a closed-loop, non-freezing system?

    The furnace is new, the heat is transferred through older baseboards, and all of the water is routed through a softener.

    Any other closed-system options or suggestions? Thank you.

    Richard

    Arcadenut@aol.com
  2. leejosepho

    leejosepho DIY scratch-pad engineer

    Do a web search for "radiant heat" and see what some engineers, installers or other technicians might advise. Here is one company with some friendly folks:
    http://www.radiantec.com/
  3. alternety

    alternety Like an engineer

    Messages:
    650
    Location:
    Washington
    From what you said about the well and softner, it sounds like you are running water through the heating system. Is it really a boiler and isolated water circulating through the system? Your heating system should already be a closed system. All you need is antifreeze of the correct type. You should know the material used in the boiler heat exchanger to pick antifreeze.

    You should never use the water from the heating system as consumable water.

    Never use automobile antifreeze.
  4. Bob NH

    Bob NH In the Trades

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    Location:
    New Hampshire
    You can use propylene glycol, sometimes called "R/V Antifreeze".

    If you have electricity in the place you could protect it to just maybe 20 F and then use electric heat to keep it above that. Houghton Lake gets pretty cold; probably -20 and occasionally to -30 F. I'm from near Gladwin so have lived through those winters.

    But how are you going to deal with the water softener and the water supply to the furnace? I would consider using electric heat to keep the whole thing above freezing. I would also put in an alarm with a phone dialer to call me if the power goes off for a long time and the temperature goes down too far. You might also want to have a local look in if there is a problem with power loss.
  5. alternety

    alternety Like an engineer

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    Location:
    Washington
    RV antifreeze does not have the addatives used in boilers and heating systems. It is not generally heated either so I am not sure how any other possible components of the RV fluid would feel about that. I would not do that if it were mine. Even after having to pay for 30 gallons of the correct stuff. Yes that is a lot, and no this is not the diluted stuff.

    Also, glycol carries less heat and is harder to pump. This will probably not be an issue unless heat capacity or pump capacity is currently right at the limit for operation. It would also be a good idea to flush the system with a cleaner before going to antifreeze. You should check the chemistry each year and put more of the antifreeze manufacturer's additives in if necessary.
    Last edited: Nov 11, 2007
  6. frenchie

    frenchie Jack of all trades

    I caretake a place on Fire Island. Now, me, I'm paranoid - so when I close up for the winter, I drain everything.

    I didn't find it complicated to refill in the spring, just time-consuming, because the place has 7 heating zones, plus 3 indirect tanks, and a heat exchanger for the pool... it takes a while to bleed the air out of 11 zones.

    Not rocket science - just a hassle.
  7. LeBlanc

    LeBlanc New Member

    Messages:
    25
    Hot Water Heat - Glycol questions

    Thank you to everyone for your replies. I'd like to clarify, just to make certain my request is clear. I have a few questions.

    Here's a photo of the system:
    http://s83.photobucket.com/albums/j306/RichardLeBlanc/?action=view&current=38.jpg



    The first item involves the hot water heat. The system is, indeed, a closed system, but it uses water and as needed it gets it from the well (on-demand). I suspect the small tank next to the furnace (about two gallons) is the "water make-up" system.

    If the efficiency is decreased, that's fine. Again, we'll probably only be there a few days during each winter and can use the natural gas fireplace for cool spring or fall days.

    What I am hoping might be an option is this:

    To ELIMINATE the water source, so that the system is filled with a fluid, is completely sealed and closed, and that it never needs additional fluid (water or anti-freeze).

    Is this realistic? Does the heat come from steam? I have never had this type of heat.

    If these systems are capable of using an anti-freeze, does it ever need a recharge or additional fluid if there are no leaks?

    Now for specific questions to the replies:

    Frenchie: If the system really can be drained and refilled with ease, how do you ensure nothing is left in this intricate system?

    Bob NH: It's the water supply to the furnace that I'm trying to eliminate (if possible). Again, I know nothing about these systems.

    I'd like to avoid anything electric. I've found electric heat sources to be too costly to use and would prefer to simply shut EVERYTHING off after draining water lines (except the heating system if it is charged with anti-freeze). I would also ensure the water softener is addressed.

    Again, thanks to everyone for the suggestions.

    Richard
  8. alternety

    alternety Like an engineer

    Messages:
    650
    Location:
    Washington
    If it is a closed system, and not steam, there should be almost no makeup water.

    The little tank is an expansion tank to absorb pressure changes as the closed system water is heated and cooled.

    The way you want it is the way it should work now. If you are using any significant amount of make-up water there is a leak.
  9. Bob NH

    Bob NH In the Trades

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    Location:
    New Hampshire
    The small tank on the heating system is an expansion tank to allow the water to expand a bit when it gets hot without causing pressure that would rupture the boiler. It has a bladder with air on one side and the boiler circuit on the water side.

    You need water makeup if you get a leak, because if it loses water the system could overheat and damage the boiler.

    You might operate the boiler to keep the place above freezing during the winter. That, along with an alarm system and an arrangement with a local caretaker might solve the problem.

    I would set up a thermostat system to operate the boiler only when the temperature is below about 40 F, and shut it down completely when it is warmer than that or when it is above 35 F outside. By completely shutting down the boiler when it is safely above freezing you will not lose a lot of heat up the stack.
  10. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
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    Location:
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    My boiler (and I'm sure some others) has a built-in anti-freeze protection. Even if it is not being asked to provide heat, if it senses it could be damaged by freezing, it will turn itself on to maintain some minimum temperature. this sort of thing is probably only available on newer, computer controlled boilers, though.
  11. alternety

    alternety Like an engineer

    Messages:
    650
    Location:
    Washington
    I believe my boiler also protects itself from freezing. But it could not operate zone valves or the circulation pumps so the rest of the system could freeze.

    Regarding loss of water. Your boiler should have a protection device to shut it down if it runs out of water. Information only; won't help you problem.
    Last edited: Nov 12, 2007
  12. frenchie

    frenchie Jack of all trades

    I blew out all the lines with a compressor. It took hours - but like I said, that house has a huge / complicated system.

    I worry about small / slow / un-noticed leak, leading to small infusions of makeup water so that I end up with a "freezable" solution in the system.

    I also worry about power outages - we had three, the winter we kept the house open & I stayed there. I know it's not electric, but it still needs power to operate the electronics, pumps, etc... If you keep it running, I think Bob's suggestions of a local caretaker's a good one, if you keep it running.

    FWIW, others who leave their houses open there, leave the thermostat set to 55 - for the margin of safety - if the power goes out, you have a day or so grace before the house & pipes cool down to freezing.
  13. BigLou

    BigLou New Member

    Messages:
    138
    LeBlanc,
    I agree with what the others have said about antifreeze the only thing I would add is that glycol will break down with time and become corosive and needs to be changed every 5 or so years maybe 10 with light use. About the boiler supply line. are you sure thats not feeding a tankless coil to provide you with hot water ? any good plumber should be able to do what you ask

    Lou
  14. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    Referenceing the Photo: The picture is not clear but that appears to be an unusual connection on the Temperature/Pressure port of the hot water heater. If the Temperature/Pressure relief valve is not permitted to discharge freely then you have a serious hazard.
  15. frenchie

    frenchie Jack of all trades

    Good eye, Bob...

    Richard - the pipes in question, are right above that damp spot on the floor in the picture. Is that all one assembly, or just look that way because one's in front of the other?

    A picture of same area, from a slightly different angle, would clear thing up.
  16. alternety

    alternety Like an engineer

    Messages:
    650
    Location:
    Washington
    It rather looks like the relief valve has a turn-off in the pipe. I tried to zoom in on that photo a few days ago but it did not work.

    One also wonders why there is water there.
  17. LeBlanc

    LeBlanc New Member

    Messages:
    25
    Hot Water Heat & PEX

    Thanks to everyone for the suggestions and advice regarding the hot water heat.

    If I remember correctly, the water evidenced in the photo is due to some minor work I was doing to replace a rubber hose with clamps to a Sharkbite connector. I'll admit, however, that the maze of pipes is very complicated and confusing.


    Additional photo's can be viewed here:

    http://s83.photobucket.com/albums/j306/RichardLeBlanc/?action=view&current=39.jpg

    http://s83.photobucket.com/albums/j306/RichardLeBlanc/?action=view&current=40.jpg

    http://s83.photobucket.com/albums/j306/RichardLeBlanc/?action=view&current=221.jpg

    http://s83.photobucket.com/albums/j306/RichardLeBlanc/?action=view&current=219.jpg


    We've only owned this place since August 2007 and recognize we may have to live with some of these things until we can have on-sight experts make recommendations.

    If there exists a hazard, I will ask someone to address it ASAP. Please explain the potential hazard referenced in the earlier post.

    One of my other posts in a different Terry Forum asks:

    I have a lot of plumbing work to do in our cottage, and it's likely I won't begin until early Spring. So, until then I'm getting all of the info I can, I'm buying supplies, and I'll keep being thankful for the advice.

    This PEX stuff seems too good to be true regarding service life and its resitance to freezing, and it's likely I'll use it everywhere I can. One thing I did notice on another site, however, is that you cannot let it become exposed to sunlight or it will deteriorate. How about indirect lighting from a bulb? Can it be painted to keep it from falling apart?


    Thanks for your help. To ensure the proper handling of my goal to avoid a freezing situation, I will consult a professional during my next visit there.

    Regards,
    Richard
  18. frenchie

    frenchie Jack of all trades

    We need pics of the other side - the water heater on the left in your original pic.

    There's a pipe that comes out of the tank's side, near the top, runs straight down towards the ground? Right above the puddle in the original picture. The bottom of that is where the problem might be. There should be nothing connected to the bottom of that pipe, it needs to be left clear. But from the angle the first picture is taken from, it looks like maybe there's a valve at the bottom of it?
  19. alternety

    alternety Like an engineer

    Messages:
    650
    Location:
    Washington
    I am not real good at heating parts identification, but in picture 40 is that small box attached to the pipe aside of the expansion tank a low water or high temperature cutoff? If it is, it needs some wires. If it is one of those devices, that is dangerous.

    The diagonal pipe at the wall from the pressure release valve on the boiler seems to just stop at the floor. Just make sure it is not blocked. If it does open water will run on the floor. If you do use glycol and that happens it will be annoying. That is the same type of assembly that is raising the questions on the other side where it looks like a relief valve feeds a pipe that has a manual valve toward the bottom. The pipe from a relief valve must never be capable of being blocked.
  20. LeBlanc

    LeBlanc New Member

    Messages:
    25
    Thanks for all of the replies and comments. Please know that I am completely unfamiliar with any of the work perform at this cottage. If it is inferior, unsafe, incorrect or otherwise bad, I'll only know it if others like you let me know.

    Below I've attached links to other photo's taken during previous trips. I believe one or more of the photo's will show the areas of potential concern. After viewing, please comment.


    http://s83.photobucket.com/albums/j306/RichardLeBlanc/?action=view&current=214.jpg

    http://s83.photobucket.com/albums/j306/RichardLeBlanc/?action=view&current=213.jpg

    http://s83.photobucket.com/albums/j306/RichardLeBlanc/?action=view&current=215.jpg

    http://s83.photobucket.com/albums/j306/RichardLeBlanc/?action=view&current=218.jpg

    http://s83.photobucket.com/albums/j306/RichardLeBlanc/?action=view&current=221.jpg


    The pipe that runs straight down off of the water heater is not plugged. It is, however, too short. An inspector recommended I lengthen it and route it into the hole where the other drain is.

    I don't know anything about expansion, pressure relief or temperature cutoff. This setup is as exactly the same as when we took possession of the property three months ago.

    We will next visit the property next week and I can take additional photo's at that time (if necessary or desired).

    Lastly, as mentioned previously, I want only to create a system that does NOT rely on the well. I am unaware whether the system ever calls for additional water, because we haven't been there enough to notice. Provided the system is leak-free, it sounds as though we can ask a professional to retrofit it to a mixed-glycol system. If you agree, please let me know.

    Thanks again.

    Richard
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